SPOCK1 and POSTN are valuable prognostic biomarkers and correlate with tumor immune infiltrates in colorectal cancer.

BACKGROUND: Immune cells and stromal cells in the tumor microenvironment play a vital role in the progression of colorectal cancer (CRC). The study aimed to screen valuable prognostic biomarkers in CRC based on stromal and immune scores. METHOD: The ESTIMATE algorithm was used to calculate the immune and stromal scores of CRC samples in TCGA. Then samples were divided into high and low score groups based on the median value of the scores. Differentially expressed genes (DEGs) associated with immune and stromal scores were screened. WGCNA and univariate COX regression analysis were performed to further identify key prognostic genes. Analysis of scRNA-seq for CRC was used for verifying the main source of the key genes. The prognostic value of they was validated based on The Gene Expression Profiling Interactive Analysis and GSE17536 dataset. TIMER and CIBERSORT algorithms were applied to analyze the correlations among key genes and tumor-infiltrating immune cells. Several pairs of colon cancer tissue were used to be proven. RESULT: 1314 upregulated and 4 downregulated genes were identified, which were significantly enriched in immune-related biological processes and pathways. Among these DEGs, SPOCK1 and POSTN were identified as key prognostic genes and mainly expressed in cancer-associated fibroblasts for CRC. High expression of SPCOK1 and POSTN was associated with advanced clinical stage, T stage, N stage, and poor prognosis of CRC. The results from CIBERSORT and TIMER revealed that SPOCK1 and POSTN were associated with tumor-infiltrating immune cells, especially macrophages and neutrophils. Meanwhile, in several pairs of human colorectal tissue samples, SPOK1 and POSTN were found to be significantly overexpressed in colorectal tissue compared with para-cancer tissue, and macrophage surface markers CD68 (co-expressed by M1 and M2 macrophages) and CD206 (M2-specific macrophage expression) were also overexpressed in cancer tissue. Besides, SPOCK1 and POSTN expression were positively correlated with the expression of immune checkpoints. CONCLUSION: Collectively, our results indicate that SPOCK1 and POSTN associated with CAF may be novel prognostic biomarkers in CRC and correlate with immune infiltrates.

MicroRNA-489-3p Represses Hepatic Stellate Cells Activation by Negatively Regulating the JAG1/Notch3 Signaling Pathway.

BACKGROUND: The transformation of hepatic stellate cells (HSCs) into collagen-producing myofibroblasts is a key event in hepatic fibrogenesis. Recent studies have shown that microRNAs (miRNAs) play a critical role in the transformation of HSCs. However, the function of miR-489-3p in liver fibrosis remains unclear. METHODS: Here, we detected the levels of miR-489-3p and jagged canonical Notch ligand 1 (JAG1) in liver fibrosis by using CCl4-treated rats as an in vivo model and transforming growth factor-beta 1 (TGF-ß1)-treated HSC cell lines LX-2 and HSC-T6 as in vitro models. The expression of profibrotic markers was affected by transfecting LX-2 cells with either miR-489-3p mimic or si-JAG1. A dual-luciferase reporter assay was carried out to study the interaction of JAG1 with miR-489-3p. RESULTS: We found that miR-489-3p was remarkably decreased while JAG1 was increased in liver fibrosis models both in vivo and in vitro. Overexpression of miR-489-3p reduced the expression of profibrotic markers and the activation of LX-2 cells induced by TGF-ß1. Moreover, miR-489-3p decreased the expression of jagged canonical Notch ligand 1 (JAG1) in LX-2 cells by interacting with its 3'-UTR. As JAG1 is a Notch ligand, decreased JAG1 by miR-489-3p inhibited the Notch signaling pathway. Moreover, the downregulation of JAG1 inhibited the expression of fibrotic markers. CONCLUSION: Our results indicate that miR-489-3p can inhibit HSC activation by inhibiting the JAG1/Notch3 signaling pathway.

Furin inhibits epithelial cell injury and alleviates experimental colitis by activating the Nrf2-Gpx4 signaling pathway.

BACKGROUND AND AIM: Furin is a proprotein convertase reported to have protective effects in several autoimmune diseases. However, the role of furin in ulcerative colitis (UC) remains unclear. We aimed to clarify this role. METHODS: Furin expression was measured in UC and dextran sulfate sodium (DSS)-induced colitis. Gain- and loss-of-function experiments were conducted to evaluate the effect of furin in UC using DSS-treated NCM460 cells. Several ferroptotic parameters, including cell viability, cell death rate, lipid reactive oxygen species level, mitochondrial membrane damage and glutathione peroxidase 4 (Gpx4) expression, were measured. Exogenous furin was used to treat the DSS-induced colitis in mice to confirm the results in vivo. Finally, the activation of nuclear factor erythroid 2-like 2 (Nrf2) was detected to explore the mechanism. RESULTS: Furin expression was aberrant in UC. Furin overexpression attenuated DSS-induced ferroptosis-like injury and upregulated Gpx4 in NCM460 cells, whereas silencing furin had the opposite effects. Exogenous furin treatment alleviated DSS-induced colitis in mice by upregulating Gpx4. Mechanistic experiments revealed that furin activated Nrf2 both in vitro and in vivo. CONCLUSIONS: Furin protects epithelial cells from DSS-induced ferroptosis-like cell injury and alleviates experimental colitis by activating the Nrf2-Gpx4 signaling pathway.